Fifth International Congress on Sound and Vibration

ABATRACT In general, it is difficult to find some large scale model only from a bottom up way viewpoint for complicated sound insultion systems like non-parallel double wall or sound-bridge type double wall. Furthermore, in the acual environment, the input fluctuates non-stationarily and the output is observed under contamination of the background noise. In this paper, for the above complicated systems with non-stationary random input, a new evaluation method is proposed by newly introducing a multiplicative-additive system model on an intensiy scale. Owing to non-Gaussian property of input, output signals and background noise, the usual identification method such as least-squares error method is not appropriate. So, a new identification method based on Kullback's information criterion is proposed to deal with the non-Gaussian property. Next, the method predicting the response output probability distribution for arbitrary random input without contamination of the background noise is proposed. Here, according to original non-negative property of intensity quantity, a statistical type I_agueme series expansion is first employed as the output probability distribution form. Its expansion coefficients can be predicted by employing the above identified model. Finally, the proposed method is experimental y confirmed too by applying it to the actual sound insulation systems.